Minimally invasive medical techniques are intended to reduce the amount of extraneous tissue that is damaged during diagnostic or surgical procedures, thereby reducing patient recovery time, discomfort, and deleterious side effects. One effect of minimally invasive surgery, for example, may be reduced post-operative hospital recovery times. Because the average hospital stay for a standard surgery is typically significantly longer than the average stay for an analogous minimally invasive surgery, increased use of minimally invasive techniques could save millions of dollars in hospital costs each year. While many of the surgeries performed each year in the United States could potentially be performed in a minimally invasive manner, only a portion of the current surgeries use these advantageous techniques due to limitations in minimally invasive surgical instruments and the additional surgical training involved in mastering them.
Minimally invasive robotic surgical or telesurgical systems have been developed to increase a surgeon's dexterity and to avoid some of the limitations on traditional minimally invasive techniques. In telesurgery, the surgeon uses some form of remote control, e.g., a servomechanism or the like, to manipulate surgical instrument movements, rather than directly holding and moving the instruments by hand. In telesurgery systems, the surgeon can be provided with an image of the surgical site at the surgical workstation. While viewing a two or three dimensional image of the surgical site on a display, the surgeon performs the surgical procedures on the patient by manipulating master control devices, which in turn control motion of the servomechanically operated instruments.
In robotically-assisted surgery, the surgeon typically operates a master controller to control the motion of surgical instruments at the surgical site from a location that may be remote from the patient (e.g., across the operating room, in a different room, or a completely different building from the patient). The master controller usually includes one or more hand input devices, such as hand-held wrist gimbals, joysticks, exoskeletal gloves or the like, which are operatively coupled to the surgical instruments that are releasably coupled to a patient side surgical manipulator (“the slave”). The master controller controls the instruments's position, orientation, and articulation at the surgical site. The slave is an electro-mechanical assembly which includes a plurality of arms, joints, linkages, servo motors, etc. that are connected together to support and control the surgical instruments. In a surgical procedure, the surgical instruments (including an endoscope) may be introduced directly into an open surgical site or more typically through trocar sleeves into a body cavity. Depending on a surgical procedure, there are available a variety of surgical instruments, such as tissue graspers, needle drivers, electrosurgical cautery probes, etc., to perform various functions for the surgeon, e.g., holding or driving a needle, suturing, grasping a blood vessel, or dissecting, cauterizing or coagulating tissue.
A surgical manipulator assembly may be said to be divided into three main components that include a non-sterile drive and control component, a sterilizable end effector or surgical tool/instrument, and an intermediate connector component. The intermediate connector component includes mechanical elements for coupling the surgical tool with the drive and control component, and for transferring motion from the drive component to the surgical tool.
While telesurgical systems, devices, and methods have proven highly effective and advantageous, still further improvements would be desirable. In general, it would be desirable to provide greater insertion axis stiffness and strength and a larger range of motion. It would also be desirable to reduce the form factor (including width and/or thickness) of the insertion apparatus near the instrument insertion site to enhance visibility for the surgical team as well as to reduce the likelihood of interference between multiple manipulator arms during a procedure.